1. Technical Field
The present invention relates to a liquid guiding device in a liquid ejecting apparatus, such as an ink jet recording apparatus, that discharges liquid from its head to spray a medium.
Liquid ejecting apparatuses are not limited to recording apparatuses, such as printers, copying machines, and facsimiles, in which an ink jet recording head is used and that discharge ink from the recording head to perform recording on a recording medium. Liquid ejecting apparatuses include apparatuses that eject, instead of ink, liquid corresponding to their uses from a liquid ejecting head corresponding to the recording head onto a medium to be sprayed corresponding to the recording medium so as to attach the liquid to the medium.
Other than the recording head, liquid ejecting heads include a color material ejecting head used for manufacturing color filters of, for example, liquid crystal displays, an electrode material (conductive paste) ejecting head used for forming electrodes of, for example, organic EL displays and field emission displays (FEDs), a bioorganic matter ejecting head used for manufacturing biochips, and a sample ejecting head used as a precision pipette.
2. Related Art
In ink jet recording apparatuses, ink is discharged from a recording head. In order to remove ink dumped outside the edges of a recording medium on a platen, a depressed portion is formed in a region of the platen facing the recording head, an ink absorber is provided therein, and ink is absorbed in the ink absorber. As shown in FIG. 10, in a known platen 101, the upstream side of a downstream portion 101a of the platen located on the downstream side of an ink dumping region 103 in the traveling direction of a recording medium is straight and has a rectangular cross section (see the portion shown by reference numeral 105) and an ink absorber 107 is provided up to this portion.
Therefore, even if ink is dumped at a position adjacent to the upstream side of the downstream portion 101a of the platen, ink is not attached on the downstream portion 101a of the platen, and ink is dumped onto the ink absorber 107. A platen having such a configuration is disclosed in, for example, Patent Document 1.
However, when the entire surface of a recording medium is sprayed with ink, the front end of the recording medium bends downward due to a large amount of attached ink, and the front end of the recording medium can collide with the upstream end of the downstream platen 101a (the portion shown by reference numeral 105). In such a case, as shown in FIG. 9, it is possible to extend part of the upstream side of the downstream platen 101a into the liquid dumping region 103, to form a guiding surface portion 109 that slopes down toward the liquid dumping region 103, and to upward guide the front end of a recording medium that is bent downward as described above.
However, in such a configuration, since the sloping guiding surface portion 109 is located in the ink dumping region 23, ink 111 remains dumped on the guiding surface portion 109 and can contaminate the underside of the recording medium.
In Patent Document 2, as shown in FIG. 11, there is disclosed a configuration in which a sloping surface 113 is formed on the upstream side of a most upstream platen 101b, and arc-shaped grooves 115 successively arranged in the vertical direction and ridges 117 between the grooves 115 are formed in this sloping surface 113. Due to such a configuration, even if ink is sprayed onto the sloping surface 113, ink accumulates in the grooves 115, and the underside of a recording medium is guided by the ridges 117, goes over the ink, and is therefore not contaminated by contact with the ink. However, the amount of ink that accumulates in the arc-shaped grooves 115 is limited. When this amount is exceeded, ink overflows the grooves 115 and can contaminate the vicinity of the platen.
JP-A-2002-86821
JP-A-7-285251